package com.rx.mine.bean;


import lombok.extern.slf4j.Slf4j;
        import org.apache.commons.codec.binary.Base64;
        import org.apache.commons.lang.StringUtils;
        import org.bouncycastle.jce.provider.BouncyCastleProvider;
        import javax.crypto.BadPaddingException;
        import javax.crypto.Cipher;
        import javax.crypto.IllegalBlockSizeException;
        import javax.crypto.NoSuchPaddingException;
        import javax.crypto.spec.IvParameterSpec;
        import javax.crypto.spec.SecretKeySpec;
        import javax.validation.constraints.NotNull;
        import java.io.UnsupportedEncodingException;
        import java.security.*;
        import java.security.spec.InvalidParameterSpecException;
        import java.util.Arrays;

/**
 * @ClassName AESUtils
 * @Description TODO
 * @Author 独狼Kiss
 * @Date 2021/9/14 13:46
 * @Version 1.0
 **/

@Slf4j
public class AESUtil {
    // 加密模式
    private static final String ALGORITHM = "AES/CBC/PKCS7Padding";
    private static final String CHARSET_NAME = "UTF-8";
    private static final String AES_NAME = "AES";

    //解决java.security.NoSuchAlgorithmException: Cannot find any provider supporting AES/CBC/PKCS7Padding
    static {
        Security.addProvider(new BouncyCastleProvider());
    }

    /**
     * 解密
     *
     * @param content 目标密文
     * @param key     秘钥
     * @param iv      偏移量
     * @return
     */
    public static String decrypt(@NotNull String content, @NotNull String key, @NotNull String iv) {
        String result = "";
        // 被加密的数据
        byte[] dataByte = Base64.decodeBase64(content);
        // 加密秘钥
        byte[] keyByte = Base64.decodeBase64(key);
        // 偏移量
        byte[] ivByte = Base64.decodeBase64(iv);
        try {
            // 如果密钥不足16位，那么就补足. 这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base
                        + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            if (ivByte.length % base != 0) {
                int groups = ivByte.length / base
                        + (ivByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(ivByte, 0, temp, 0, ivByte.length);
                ivByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", "BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters
                    .getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                result = new String(resultByte, "UTF-8");
            }
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidParameterSpecException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (InvalidAlgorithmParameterException e) {
            e.printStackTrace();
        } catch (NoSuchProviderException e) {
            e.printStackTrace();
        }
        return result;
    }

}